Lectures notes for 2010 - KTH

Subnet mask
32 bit value with a 1 for NetID + subnetID, 0 for HostID
16 bits 8 bits 8 bits
NetID SubnetID HostID
1111 1111 1111 1111 1111 1111 0000 0000
Figure 29: Class B address with a 8 bit subnet address
2 different class B subnet arrangements
16 bits 8 bits 8 bits
NetID SubnetID HostID
1111 1111 1111 1111 1111 1111 0000 0000
0xffffff00
255.255.255.0
/24
16 bits 10 bits 6 bits
NetID SubnetID HostID
1111 1111 1111 1111 1111 1111 1100 0000
0xffffffc0
255.255.255.192
/26
Maguire Subnet mask 1: 93 of 104
maguire@kth.se 2010.03.21 Internetworking/Internetteknik